1. Field of the Invention
The present invention relates to a valve timing adjusting device for adjusting open/close timing of an intake valve or an exhaust valve of an engine, a manufacturing apparatus for manufacturing the valve timing adjusting device and a method for manufacturing the valve timing adjusting device.
2. Description of Related Art
There are known valve timing adjusting devices configured to adjust open/close timing of an intake valve or an exhaust valve of a vehicle engine by varying the rotational phase between the crankshaft (driving shaft) and the camshaft (driven shaft) of a vehicle engine.
For example, Japanese Patent Application Laid-open No. H9-209722 describes a valve timing adjusting device which includes a sprocket receiving torque from a crankshaft, a vane rotor fixed to the camshaft, a housing with an oil chamber housing the vane rotor, and a sleeve disposed rotatably relative to the camshaft. A knock pin is inserted into a hole formed in the sleeve, a hole formed in the sprocket and a hole formed in the housing. The sprocket, the housing and the sleeve are fastened to one another by this knock pin and a bolt so that they can rotate together.
However, there is a slight clearance between the inner wall of the hole of the sprocket and the knock pin depending on tolerance of the inner diameter of the hole of the sprocket and the outer diameter of the knock pin. Further, there is a slight clearance between the inner wall of the hole of the housing and the knock pin depending on tolerance of the inner diameter of the housing of housing and the outer diameter of the knock pin. Incidentally, the vane rotor of the valve timing adjusting device may be at the intermediate phase position while the engine is stopped. In addition, generally, the oil in the oil chamber of the valve timing adjusting device is evacuated therefrom while the engine is stopped. Accordingly, since the oil flows into the oil chamber rapidly when the vane rotor is phase-controlled to its starting position at the time of engine start, there is a concern that the vane rotor may collide with the inner wall of the oil chamber, causing positional deviation between the housing and the sprocket If the positional deviation causes the bolt fixing the sprocket, housing and the sleeve to be loosened relative to each other, it may be difficult for the valve timing adjusting device to control the phase between the crankshaft and the camshaft.